Agricultural chemicals such as pesticides, bactericides, plant growth hormones, and herbicides can exert their effects only by being absorbed into a body of a plant, an animal such as an insect, or the like. However, both plants and insects often have a water-repellant property to reject an aqueous agricultural chemical solution such that plants have a wax lipoid-secreting, a fuzzy surface, or a finely irregular surface, and insects have a layer similar to a keratin layer on the surface. Agricultural chemicals thus face the problem of failing to achieve desired effects when applied.
For the purpose of covering the problem, agricultural chemical-spreading agents have been widely used in the field of agriculture, particularly in emulsions and wettable powders of agricultural chemicals, to improve wetting and spreading performances thereof. The agricultural chemical-spreading agent contains a surfactant as a principal ingredient and reduces the surface tension of an agricultural chemical composition with the surfactant to improve wetting and spreading performances of the composition, and in practical use, further influences physical properties of the composition such as of emulsifying, dispersing, penetrating, fixing, suspending, and defoaming. The spreading agent for an agricultural chemical is thus an important adjuvant.
Examples of the agricultural chemical-spreading agent having been conventionally known include nonionic surfactants such as polyoxyethylene sorbitan esters, polyoxyethylene alkyl (or aryl)ethers, and polyoxyethylene fatty acid esters; anionic surfactants such as linear alkylbenzenesulfonates, dialkylsulfosuccinates, lignin sulfonates, and polynaphthyl sulfonates; and polymers such as polyacrylates.
For example, JP-A06-329503, JP-A09-278605, and JP-A10-231202 describe use of a specific nonionic surfactant produced by adding an alkylene oxide in an agricultural chemical-spreading agent. JP-A2000-001404 discloses an agricultural chemical-spreading agent composition containing a sorbitan fatty acid ester, a polyoxyethylene alkyl ether, and a polyether-modified silicone at specific proportions. JP-A2001-288006 discloses an agricultural chemical-spreading agent composition containing two surfactants having different melting points and describes that the spreading agent composition has a good stability at low temperature. JP-A2007-176855 discloses an agricultural chemical-spreading agent composition containing a cationic compound and an anionic oligomer or polymer, in which an anionic residue of an acid group serves as a counter ion of the cationic compound. Furthermore, JP-A2005-132741 proposed a water-dispersible granule for agriculture and horticulture, containing a cellulose derivative having a viscosity of 10 to 2000 mPa·s in the form of 2% by weight aqueous solution as a fixing agent in order to prevent an agricultural chemical from running off from a leaf or the like due to rainfall or the like.
JP-A09-077617 discloses use of a milbemycin compound to promote effects of an active ingredient, thereby preventing pines from dying. JP-A09-110617 discloses use of tebufenpyrad to promote effects of an active ingredient, thereby preventing pines from dying. JP-A11-147803 discloses use of pyrimidifen to promote effects of an active ingredient, thereby preventing pines from dying. JP-A11-071202 discloses a bactericide composition containing a bactericide and soluble starch. JP-B2009-522332 discloses a liquid concentrate containing a difficulty soluble, organic agricultural chemical compound and a solvent mixture. WO-A2008/032671 discloses a pest control agent in a suspension form, containing a cationic pest control active ingredient or an acid, a nonionic thickener, a nonionic surfactant, a solid active ingredient, and water.